Which flame color indicates the presence of sodium ions?

Which flame color indicates the presence of sodium ions?

• A. Blue
• B. Green
• C. Yellow
• D. Lilac

Answer: (C)

Sodium ions give a bright yellow flame when heated. In flame tests, the heat excites the electrons, and when they return to lower energy levels they emit light at specific wavelengths. For sodium, the emitted light is a strong yellow color around 589 nm, which is very characteristic and often dominates other colors in a sample. That distinctive yellow makes it the telltale sign of sodium ions. Other ions produce different flame colors—green with barium, lilac with potassium, blue with copper—so the yellow color specifically points to sodium. In mixtures, sodium’s intense yellow can mask other colors, but its presence is clearly identified by that unmistakable yellow flame.

Sodium ions give a bright yellow flame when heated. In flame tests, the heat excites the electrons, and when they return to lower energy levels they emit light at specific wavelengths. For sodium, the emitted light is a strong yellow color around 589 nm, which is very characteristic and often dominates other colors in a sample. That distinctive yellow makes it the telltale sign of sodium ions.

Other ions produce different flame colors—green with barium, lilac with potassium, blue with copper—so the yellow color specifically points to sodium. In mixtures, sodium’s intense yellow can mask other colors, but its presence is clearly identified by that unmistakable yellow flame.